Warning: engaging [rant mode]. Proceed at your own risk.
I agree that a considerable portion of the prestige classes out there are mindless, flavourless pulp. It's acually got worse in 3.5. I looked at the new DMG, and almost cried. I mean, they say prestige classes should be special, right? They shouldn't have to be *better* than base classes; although these days, they generally are; they should have to be *different*. And then they throw us the Mystic Theurge and Eldritch Knight. I mean, come on, people! Unique abilities? No. Interesting flavour? No. All these classes do is let you be a wizard AND a cleric, or an arcane caster AND a fighter. There's no personality, no originality, no nothing to these classes at all! Even the Arcane Trickster, functionally a rogue/arcane caster, has a few class-specific abilities!
And then they go and create prestige classes which are just damn stupid, like the Incantatrix and Dweomerkeeper. I mean, look at the Dweomerkeeper. *How* in the name of the Nine-Headed Serpent of Vhuul did they ever think this was a balanced class? A spell as a supernatural ability up to FIVE time a day?! No SR, no components?! Able to cast one spell of each level spontaneously?! All you need's a bloody cleric of Mystra with the Arcane Schooling regional feat, and you qualify for the class's spellcasting prereqs! Then, you can take the Initiate of Mystra feat, and choose Anyspell as a spell you can cast spontaneously! The mind boggles at such an abuse of power!
As for the Incantatrix...apart from their stupid, stupid powers, look at their ability to apply metamagics to spell trigger items. You could have an Incantatrix 'wandslinger' who never needs to cast spells; he merely throws Twinned Empowered Maximised Quickened Enervations at people from his wands! Sure, he burns them out fast, but hey, he can nuke practically anything! And all he has to do is carry a Wand of True Strike and have Quicken Spell, and he has ten Quickened True Strikes for a cost of 750 gp until Incantatrix 7, where he gets 12 per wand due to his reduced cost of metamagics! A friend of mine's been mentioning relics in combination with this, and though I don't have the Complete Divine yet, if what he's been telling me about relics is true, this gets even sillier. Making items cheaper or for free by giving up spell slots? Sure! Not like I need them, with 6 staves of Zapping Death! I don't even cast spells myself anymore!
[disengaging rant mode]
*sigh* I just wonder what the point is. I don't know what some of the designers are smoking, but a lot of the prestige classes out these days seem flavourless, overpowered, or both. There are notable exceptions. Horizon Walker is interesting, fun, and strong without being overpowered. Divine Disciple (from Players Guide to Faerun) is also a class which has its highlights.
Duellist has some meat to it, though I prefer the Swashbuckler base class from Complete Warrior. Several other PrCs have interesting, unique powers without selling their originality or balance down the river. But a lot of the arcane based prestige classes especially seem either stupidly good or pointless, with no redeeming features.
In summary:
1) Less boring PrCs.
2) less broken PrCs.
would make things considerably better. However, I don't see it happening..and until designers start choosing quality over quantity in PrC design, I get the feeling that our weariness with PrCs will only increase.
Sorry for the ranting. Hope I didn't bother anyone getting that off my chest.
Cheers,
Synchronicity.